Lubricating fitting



Patented Oct. 15, 1940 i UNITED STATES PATENTl AOFFICE'. 2,217,738 v v LUBRICATING Firme I Fred .Henry hnts, Lansdowne, Pa., assignor to Keystone Lubricating Company, Philadelphia, Pa., a corporation of Pennsylvania Application July so, 193s, serial 120.222.101

1 claims. '(cl. isi-rosy My present invention relatesv t'o fittings for low 'l pressure lubrication 'for ball and roller bearings,

and aims to provide certain improvements therein. More particularlyit'relates to such fittings 5 which provide a Ytell-talepr indication when the bearing being"l'u'ioicatellhas ,been supplied with the requisite, amount of grease. Furthermore, it

constitutes an improvement over Acertain 'features of the invention disclosed in my'co-pending application, Serial No. 203,01l,-led April 20, 1938.

kThe practice' heretofore conventionally fcl-v rlowed in the lubrication of kball and roller bearings with grease has been to inject the grease l under pressure into a bearing, either bymeans 15 of a high' pressure grease gun through afliigh pressuretting, or'by a hand compression cup. lWith either devicethe risk of under-lubrication is obvious. Even more serious, however, is the danger of over-lubrication, which results in powl .120 er losses, overheating caused by internal friction,

and excessive wear, theA placingof undue stresses on the bearing races andthe wasting of lubricant.

Recognizing these inherent I dangers, bearing manufacturers recommend that ball and-roller bearings be charged no more'than' two thirds full of grease, and preferably only one third to onehalf full. f v

Until quite recently no means were available for indicating when a bearing has been properly 0 charged with viscous lubricant, and one had to trusll to chance that enough, and not too much,

grease had been supplied to a bearing. This was especially true where the bearings were located at inaccessible placeswhich necessitated the use of extension tubes leading from the bearingsand through which the grease had to be supplied'tof thev bearings.

My present invention has for its primary object the provision of a fitting which can be embodied 40 in or used with an extension tube and thereby provide a tell-tale for insuring proper lubrication of bearings located at remote and inaccessible points. A further object is to provide a tell-tale tting for lubricating a plurality of spaced-apart bearings from a point remote from the bearings. A further' object is to provide such fitting which will be simple inconstruction, with noparts subject to becoming dislocated `in use,` and hence l foolproof in operation. In my co-pending application above referredl to I have shown and described a fitting intended to n accomplish the stated object yof the present inventiomand althoughthe fitting disclosed therein accomplished said objects to a certain degree I have discovered that, because -ofirregularities in tained therewith would be uniform, I provide. the

fitting with two substantially concentric ,tubes 10 and rely u/ponthe skin friction of the adjacent 'walls of .these tubes for building up the necessary resistance to the back flow of grease` from abearingto the tell-tale opening in the fitting. for indicating when` the predetermined amount of 15 grease or back pressure built up thereby has been obtained, instead ofgrelyi'ngvupon the uncertain internal diameter and wall condition of ordinary iron pipe conventionally used as extension members. 'Ihe invention will be better understood 20 from the detailed description which follows, when considered in conjunction with the accompanying drawing, wherein:

Figure 1 is a side elevation partly in section, of

my invention applied to an extension .tube con-` 25 nected to a bearing.

Fig. 2 is a diametrical section on an enlarged. scale `lof a similar'titting intended for use with a shorter extension tube than shown in Fig. l.

Fig. 3 is a section taken substantially along the 30 plane of the line 3-3 of Fig. 2. v v y,

Fig. 4 is a section taken substantially along the plane of the line 4 4 of Fig. 2.

Fig. 5 is a view somewhat similar to Fig. 2 of a slightly modified form of construction. y

Figs. 6 and 7 are diametrical sections lshowing still further modifications. n

. Fig. 8 shows an application of my invention to lubricating spaced apart bearings.

Referring iirst to Figs. l to 4 of the drawing, 40 the fitting may be said-to consist of a tubular casing I0,herein shown as being of hexagonalcrosssectionfand having a bore therethrough of progressively increasing diameter fromr theA toptov 5f through leading from the bore I5 to the exterior of the casing. for a purpose which will be presently described.` At its lower end the casingissome- 55 what reduced in diameter and externally screwthreaded, as indicated at II.

Disposed within the casing and extending from a point above the shoulder I4 through the bottom of the casing is a tubular element I8 which may be held within the casing by being secured to a washer I 9', which, in turn, may be force-iitted into the bore I3 to seat against the shoulder", or held within the casing in any desired manner. This tubular element I8 serves as the duct through which viscous lubricant which is received through the top of the casing from a suitable source (not shown) is supplied to a tubular extension member or pipe I9, one end 20 of which is connected or adapted for connection to a housing 2| of a bearing or other member to be lubricated. The opposite end 22 of the tubular extension member may be suitably connected to the casing I8 by a coupling sleeve 2l. The construction thus far described is substantially similar to that disclosed in Figs. 5 andl 6 oi' my co-pending application above referred to.

To insure and accurately control the back pressure at which viscous lubricant charged into the tubular extension member I8 when connected to a bearing housing 2| or the like, will back up and exude through the openings I8 leading from the chamber formed between the wall of the bore I5 and the outer wall of the tubular element I8, I provide a second tubular element 24 disposed in substantially concentric spaced relation to the tubular element I8, the said tubular elements I8 and 24 terminating ilush at their lower ends. The cross-sectional area between the tubular elements I8 and 2-4 and the length of said elements are calibrated with respect to the length of the extension member with which they are used t0 provide the necessary resistance to the back ow of the lubricant to permit the lubricant to exude out of the openings` I6 when the lubricant being charged into the bearing housinghas built up the desired back pressure.

,As shown in Fig. J3, the tubular element 24 is force-fitted or otherwise xedly held within the bore I5 of the casing III. In Fig. 5 I have shown the bore I5 at its lower end as being somewhat enlarged, as indicated at 25, and the tubular element 24 force-ttedinto said enlarged portion so that the internal wall of the tubular element 24 vis substantially flush with the bore I5. It will, of course, be understood that where this latter arrangement is resorted to. the cross-sectional area between the tubular elements1 I8 and 24 maybemadethesameasinFig. 2, orifsaid area'differs therefrom, the lengths of the tubes will be modified, as found necessary. If desired, instead of forming the tubular element 24 as a separate member and securing it to the casing I0, said casing may be' formed with a tubular axial extension 24* to engage within the tubular extension memberfll, as shown in Fig. 6, or said extension member may be formed at its free emi with .screw-thresatds,A as indicated at 21, for direct attachment tothe end Vof the tubular ex tension member Il, as shown in Fig. 7. Obviously the axial tubular extension may be so dimensioned as to'screw-threadedly engage either internal or external screw-threads on the extension member. I9.

In the various embodiments of'my invention shown. the degree' to which the concentric tubular elements extend intov the extension-member will vary as the length of the extension member varies and further, I have found that the ratio of increase in the lengths of the concentric tuon the casing.

\ that the complemental surfaces of the tubular elements I8 and 24 or 24 be smooth so that the resistance. offered thereby to the passage of the viscous lubricant between the tubular elements will be substantially constant under similar conditions and dimensions of tubular elements employed. In the use of my invention as hereinbefore described, the fittings, i. e., the casing I8 and the tubular elements I8 and 24 or 24',I will be marked with numbers corresponding to the length in inches of the extension members with which they are to be used, and it will be merely necessary to attach a tting provided with proper designation of extension tube length to such extension tube and apply the lubricant to the charging end thereof until the lubricant exudes or is discharged fromthe openings I6. It is preferable, however, to first remove the extension member from the bearing and to charge the lubricant therein through the charging end of the tting, holding the nger over the discharge end of the extension member until the tell-tale discharge of lubricant through the openings I8 is obtained. The extension member is then screwed into the bearing and the charging of the bearing is proceeded with until* the lubricant again issues forth from the openings 22 for at least a quarter of an inch, thereby giving an lindication that the ybearing is adequately lubri- -be apparent that I have devised'a simple, efflcient and practical fitting for insuring proper lubrication of ball and roller bearings and bearings at spaced apart points; and for providing a visible tell-tale for indicating when the bearings have been adequately lubricated, a'nd while I have shown and described certain preferred embodiments of my invention it is to be understood that I do not wish to be limited to the speciiic constructions disclosed since the same may be varied within the range of engineering skill without departing from the spirit of my inven' tion.

What I claim is:

1. A lubricating tting' comprising a tubular casing having at its top means for engagement with a source of viscous lubricant, meansl below its top through which the casing is attachable to a membwer for receiving the lubricant uponl discharge from the fitting, a tubular element dis'- posed within the bore of said casing below the top thereof in spaced relation to the wall of said bore, said casing having an opening therein in proximity to the top of the casing providing open communication between the exterior of the casing and the space between the wall of the casing bore and the outer wall of the tubular element and said casing having a tubularv axial extension -encircling the tubular element in substantially concentric relation thereto of a `length to extend a vsubstantial distance from the opening in the casing, the various parts of the tting bein `fixed relatively to one another in use.

2. A lubricating fitting according to claim 1,

wherein the tubular axial extension terminatesl wherein the tubular axial extension on the casing is formed separately from the casing and held thereto by being force-fitted into the bore of the L casing.

6. A lubricating fitting comprising a tubular casing having at its top means for engagement with a source of viscous lubricant, means vbelow itstop for attachment to a tubular extension member adapted for connection with a member for receiving the lubricant upondischarge from the tubular extension membera tubular element disposed within the bore of said casing below the top thereof in spaced relation to the Wall of said bore. said casing having an opening therein in proximity to the top of the casing providing open communication between the exterior of the casing and the space between the wall of the casing bore and the outer wall of the tubular element and said casing having a tubular'axial extension in substantially concentric relation to-the tubular element extending from a point within the casing below the opening therein, down into the tubular extension member.

7. A tell-tale lubricating fittingior indicating at a point remote from` a bearing housing to be lubricated when said bearing housing has been properly lubricated, comprising a tubular extension member one end of which has means for attachment to a bearing housing for receiving viscous lubricant, two substantially concentric tubular elements within the tubular member, said concentric tubular elements each having one end spaced rearwardly of the discharge end of the tubular extension member and having the other end terminating in a casing having means for engagementn with a source o! viscous lubricant which is adapted to be discharged through the inner tubular element into the tubular extension member and from there into the bearing housing, said casing having an opening therein providing open communication between the exterior thereof and the space between the walls of the concentric tubularv elements.

FRED HENRY EHNTS. 

